/Engine/Plugins/2D/Paper2D/Source/Paper2D/Public/AlphaBitmap.h
Checks the image to determine if it is suitable for opaque, masked or translucent rendering.
void AnalyzeImage ( int32 StartX, int32 StartY, int32 InWidth, int32 InHeight, bool & bOutHasZeros, bool & bOutHasIntermediateValues ) const